The present invention relates to labels for optical discs such as CDs, CD-ROMs, CD-Rs, CD-RWs, DVDs, etc. More particularly, it relates to an optical disc label including a phosphorescent material that provides a glow-in-the-dark property, and a method of preparing the same.
Optical discs are a highly popular medium used to record and electronically store data in various forms such as text, graphics, audio, video, etc. Examples of available optical disc formats include CDs, CD-ROMs, CD-Rs, CD-RWs, DVDs, etc. When optical disc technology was first introduced, only source manufacturers could program individual optical discs, and typically did so on a mass production basis. Once formatted with the desired data, the optical discs were provided to consumers with some form of printed identification information on an outer surface thereof. Because the optical discs were mass produced, it was economically feasible, and from a marketing standpoint highly desirable, to imprint stylized identification information into the optical disc's surface. While this practice is still followed today, more recently consumers have been afforded the ability to “burn” their own optical discs. That it is to say, it is now possible for a consumer to record desired data onto an otherwise “blank” optical disc. Once formatted, the user will almost certainly desire to provide some form of identification information at an outer surface of the optical disc. Unlike mass-produced, programmed optical disc manufacturers, the average consumer cannot imprint identification information to the optical disc's outer surface. Instead, consumers typically make use of a separately provided label.
In general terms, optical disc labels are formed from paperstock, with an adhesive backing for securing to a top face of the optical disc. The paperstock is normally white, and provides a surface onto which the user can hand write identification information with a writing utensil such as a pen or marker. More recently, computer programs have been developed that allow users to independently create highly stylized, professional-quality designs formatted for printing on a corresponding optical disc label. To this end, the label is provided as part of a label sheet that is otherwise sized for use with a printer, such as an inkjet printer. The user simply loads the label sheet into the printer, operates a linked computer to create the desired labeling design or image, and then prompts the printer to print the so-created design or image onto the label. Optical disc labeling software and printer technology has now evolved to the point that high resolution labeling designs can be created and printed to the label surface. To satisfy this intended use, the paperstock material employed with current optical disc labels is typically provided in a form that can maintain the resolution quality of inkjet printer-generated images. That is to say, consumers demand that ink applied to the optical disc label by a printer (such as an inkjet printer) not “bleed” or “run”; this is typically accomplished by utilizing inkjet printer receptive paper for the optical disc label.
Regardless of exact form, once applied, the optical disc label readily identifies to the user the contents of the optical disc. Under certain circumstances, however, the identification information may not be decipherable, for example, in a darkened environment. In fact, not only is it difficult, if not impossible, to read the label in the dark, users may experience difficulties even locating and/or handling the optical disc. This is an all-to-common experience when riding in an automobile during the night.
The above-described concern has been the subject of investigative efforts in the unrelated field of tape cassette labeling. In particular, a rectangular tape cassette label having a light-storing layer formed on top of a paper base layer is described, for example, in U.S. Pat. No. 6,048,595 to Nakajima et al. (“Nakajima”). The separate light-storing layer emits stored energy as light in darkened environments. Though potentially useful for labeling of tape cassettes, tape cassette labels such as that of Nakajimi are simply inapplicable for optical discs. Unlike a tape cassette, uniform placement or alignment of a separately provided label relative to the optical disc itself is highly important. In particular, an applied label that creates a radial or circumferential imbalance across the optical disc can lead to improper operation of the optical disc within an associated drive. Thus, the rectangular tape cassette label of Nakajima (and tape cassette labels in general) do not account for the delicate balancing required of optical disc labels. Further, because tape cassette labels are relatively small as compared to optical disc labels, little or no efforts have been made to create software programs capable of producing high resolution, inkjet-generated images on tape cassette labels. As such, the Nakajima tape cassette label (and similar references) fails to provide an outer surface that readily accepts and maintains inkjet printer-generated designs. Instead, the outer, writeable surface is less robust, likely formed to receive markings from a conventional ink pen.
Consumers continue to demand high quality yet inexpensive labels for labeling of optical discs. Unfortunately, currently available optical disc labels do not allow for viewing thereof in a darkened environment, and proposed solutions for tape cassette labeling fail to address the specific constraints of the optical disc environment. Therefore, a need exists for an optical disc label configured to provide a glow-in-the-dark property that does not negatively affect optical disc performance.